/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.phoenix.repository.query.jql;

import javax.jcr.query.InvalidQueryException;
import javax.jcr.query.qom.Source;

/**
 * Jigsaw server
 * 
//## fromClause:
//##    FROM className AS? identifier (  ( COMMA className AS? identifier ) | ( joinType path AS? identifier ) )*;

// NOTE: This *must* begin with the "FROM" token, otherwise the sub-query rule will be ambiguous
// with the expression rule.
// Also note: after a comma weak keywords are allowed and should be treated as identifiers.

fromClause
	: FROM^ { weakKeywords(); } fromRange ( fromJoin | COMMA! { weakKeywords(); } fromRange )*
	;

//## joinType:
//##     ( ( 'left'|'right' 'outer'? ) | 'full' | 'inner' )? JOIN FETCH?;

fromJoin
	: ( ( ( LEFT | RIGHT ) (OUTER)? ) | FULL | INNER )? JOIN^ (FETCH)? 
	  path (asAlias)? (propertyFetch)? (withClause)?
	;

withClause
	: WITH^ logicalExpression
	;

fromRange
	: fromClassOrOuterQueryPath
	| inClassDeclaration
	| inCollectionDeclaration
	| inCollectionElementsDeclaration
	;
	
fromClassOrOuterQueryPath!
	: c:path { weakKeywords(); } (a:asAlias)? (p:propertyFetch)? {
		#fromClassOrOuterQueryPath = #([RANGE, "RANGE"], #c, #a, #p);
	}
	;
 * @author    <a href="shamphone@gmail.com">Li XiongFeng</a>
 * @date      2012-4-22
 * @version   1.0.0
 */
public class FromClauseAST extends JQLBaseAST {

	/**
	 * 
	 */
	private static final long serialVersionUID = 5854846303502059085L;
	
	public Source getSource(){
		if(this.getNumberOfChildren()==1)
			return (Source)this.getFirstChild();
		Source left = (Source)this.getFirstChild();
		JoinAST right = (JoinAST)this.getFirstChild().getNextSibling();
		while(right!=null){
			right.setLeft(left);
			left = right;
			right=(JoinAST)right.getNextSibling();
		}
		return left;		
	}

	@Override
	public String toJQL() {	
		return " FROM " + super.toJQL();
	}

	/* (non-Javadoc)
	 * @see net.phoenix.repository.query.parser.JQLBaseAST#generateSQL(net.phoenix.repository.query.parser.JQLQuery)
	 */
	public void generateSQL2(JQL2SQL collector) throws InvalidQueryException{
		StringBuffer buffer= new StringBuffer("");
		JQLBaseAST child = (JQLBaseAST)this.getFirstChild();
		while(child!=null){
			child.generateSQL(collector);
			if(buffer.length()>0)
				buffer.append(",");
			buffer.append(collector.pop());
			child = (JQLBaseAST)child.getNextSibling();
		}
		buffer.insert(0, "FROM ");
		collector.push(buffer.toString());
	}


	/* (non-Javadoc)
	 * @see net.phoenix.repository.query.parser.JQLBaseAST#generateSQL(net.phoenix.repository.query.parser.JQLQuery)
	 */
	@Override
	public void generateSQL(JQL2SQL collector) throws InvalidQueryException{	
		JQLBaseAST from = (JQLBaseAST) this.getFirstChild();
		while (from != null) {
			from.generateSQL(collector);
			from = (JQLBaseAST) from.getNextSibling();
		}
	}
}
